<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>flex</title>
    <link rel="stylesheet" href="../../css/bootstrap.min.css">
    <link rel="stylesheet" href="../../bootstrap-icons-1.13.1/bootstrap-icons.min.css">
    <script src="https://code.jquery.com/jquery-3.5.1.slim.min.js"></script>
    <script src="https://cdn.jsdelivr.net/npm/popper.js@1.16.1/dist/umd/popper.min.js"></script>
    <script src="../../js/bootstrap.bundle.min.js"></script>
    <style>
        .dd{
            width:100px;
            height:100px;

        }
    </style>
</head>
<body>
    <div class="container d-flex flex-row  bg-secondary justify-content-center">
        <div class="dd bg-primary m-3">1</div>
        <div class="dd bg-success m-3">2</div>
        <div class="dd bg-dark m-3">3</div>
        <div class="dd bg-danger m-3">4</div>
    </div>
</body>
</html>